BIRDS OF NORTH AND MIDDLE AMERICA. 87 



bli. Greater wing-coverts not edged with white; upper tail-coverts not partly 

 white, 

 c. Axillars and under wing-coverts white or very pale gray; general color of 

 upper parts in adults greenish blue or bluish green. 

 d. Smaller (wing not more than 105 mm.); feathers of rump with dusky 

 shaft-lines, those of upper back white beneath surface. (Southern Mex- 

 ico to Peru) Iridoprocne albilinea (p. 90) 



d(l. Larger (wing more than 110) ; feathers of runi]) without dusky shaft- 

 lines, those of upper back gray beneath surface. (Southern Brazil to 



Patagonia and eastern Peru) Iridoprocne leucorrhoa (extralimital)" 



cc. Axillars and under wing-coverts light grayish brovvn or l>ro\vnish gray; gen- 

 eral color of upper parts violaceous steel blue. (Chile and southern Pata- 

 gonia to western Bolivia) Iridoprocne meyeni ( extra! iniital) b 



IRIDOPROCNE BICOLOR (Vieillot). 

 TREE SWALLOW. 



Adult male. — Above, including' sides of liead and neck, and le-sser 

 wing-coverts, uniform glossy greenish steel blue, varying to bluish 

 green, sometimes with a slight tinge of bronzy green; middle wing- 

 coverts dull black, broadly margined with glossy steel blue or green- 

 ish; rest of wings, and tail, dusky, or soot}' blackish, faintly glossed 

 with greenish; lores velvet}^ black; malar region and entire under 

 parts pure white; axillars and under wing-coverts brownish gray, the 

 latter becoming paler toward edge of wing; bill black; iris brown; 

 legs and feet brownish or horn color; length (skins), 122-138 (132.6); 

 wing, 111-125 (117.1); tail, 51-60 (55.7), forked for 7.5-11.5 (8.9); 

 exposed culmen, 5.5-7 (6.3); width of bill at frontal antite, -1.5-6 (1.9); 

 tarsus, 11-12.5 (12); middle toe, 10.5-12.5 (11.5).^ 



Adult female. — Similar to the male, and sometimes not distinguish- 

 able, but usualh^ duller in color, the upper parts less brightly 

 steel blue or green, often dusky grayish brown with only the tips of 

 the feathers gloss}^ blue or green; the rump and upper tail-coverts 

 sometimes uniform grayish brown; chest often faintly shaded with 

 brownish gray; length (skins), 125-141 (132.1); wing, 109-122 (113.5); 

 tail, 51-58 (54.5), forked for 7-11.5 (8.4); exposed culmen, 6-7 (6.2); 



1865, 302.— Tarhycmetn alhwentrin Shar])e, Cat. Birds Brit. Mus., x, 1885, 113; Sharpe 

 and Wyatt, :Mon. Hirund., 1894, 138, pi. 20.— Iliniudo leacoptera Gmelin, Syst. Nat., 

 i, pt. 2, 1788, 1022 (same basis as //. albircntris Boddaert). 



(illh-undo leucorrhoa Viellot, Nouv. Diet, d'llist. Nat., xiv, 1817, 519 (Paraguay; 

 based on Golondrina rahadUla blanca Azara, A])unt. Parag., ii, 509); Baird, Review 

 Am. Birds, 1865, 301.— Tachycineta leucorrhous Sharpe, Cat. Birds Brit. :Mus.,x, 1885, 

 114; Sharpe and Wyatt, Mon. Hiruud., 1894, 143, pi. 21.— Ilirundo frontalis (not of 

 Quoy and Gaimard) Gould, Proc. Zool. Soc. Lond., 1837, 22 (Montevideo, Uruguay; 

 coll."Zool. Soc. Land.).— Hirundo gouldii Cassin, Proc. Ac. Nat. Sci. Phila., 1850, 69 

 (new name for II. frontalis Gould, preoccupied). 



b Pldrochelidon'} meyem Cnhnnis, Mus. Hein., i, 1850, 48 (Vh\\e).—Hirundo meymi 

 Baird, Review Am. Birds, 1805, 302.— T<ichyri)uia meyrni Sharpe, Cat. Birds Brit. 

 Mus., X, 1885, 116; Sharp and Wyatt, Mon. Hirund., 1894, 153, pi. 23. 



''Sixteen specimens. 



